Bleaching machine



Oct. 6, 1925.

A. D. MERRILL BLEAGHING MACHINE 2 Sheets-Sheet 1 Filed June 10. 922

A. D. MERRILL Oct. 5, 1925.

BLEACHING MACHINE Filed June 10. 1922 2 Sheets-Sheet 2 Patented Oct. 6, 1925.

UNITED STATES PATENT OFFICE.

ALBERT D. MERRILL, OF WATERTOWN, NEW YORK, ASSIGNOR TO S'IEBBINS ENGI- i NEERING & MFG. 00., OF WATERTOWN, NEW YORK.

BLEACHING MACHINE.

Application filed .Tune 10, 1922. Serial No. 567,296.

To all whom it may concern:

Be it known that I, ALBERT D. MERRILL,

a citizen of the United States, residing at Watertown, in the county of J elferson and State of New York, have invented a new and usefulBleaching Machine, of which the following is a specification.

This invention relates to apparatus designed primarily for bleaching pulp used in making paper, one of the objects of the 1nvention being to provide means for setting up a forced'circulation of the pulp successively within vats or tanks contalning a bleaching agent, novel means being prov1d- 1 ed for conveying the pulp from one of these vats or tanks to the next one of the series after it has been properly circulated therein. Another object is to provide bleaching apparatus in the form of a continuous system that will handle'stock of a greater or higher density than has been possible heretofore, this stock being subjected to a forced circulation whereby a product of more uniform quantity and quality is obtained, delays in operation are eliminated, the bleaching agent is economized, the stock is aerated and thoroughly mixed, thereby to quicken the bleaching operation, and the capacity of the apparatus 1s increased economically.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that, within the scope of what is claimed, changes in the precise embodiment of the invention shown can be made without departin from the spirit of the invention.

In t e accompanying drawings the pre' ferred form of the invention has been shown.

In said drawings- Figure 1 is a plan view of a portion of the apparatus, one complete unit and portions of two additional units being 1llustrated.

' Figure 2 is a side elevation of one of the p units.

Referring to the figures by characters of reference 1 designates a tank or vat formed of concrete or any other suitable material and having one end portion reduced gradually both in width and height to an outlet pipe 2 which discharges into the casing 3 of a standard bleach propeller which, when in operation, serves to direct stock from the pipe 2 into delivery pipes 4 extending .from the end portions of the casing 3 as shown. As I the bleach ropeller is of a standard make and constitutes in itself no part of the present invention, it 'is not deemed necessary to show or describe it in detail. The pipes 4 are preferably tapered toward casings 5, as shown particularly in Figure 2 and opening into each of these casings 5 is a pipe 6 adapted to supply air, gas or other fluid under pressure. Pipes 7 extend from the casings 5 and open into the back end of the vat or tank 1 at the sides thereof, the back wall of this vat or tank having rounded faces 8 whereby when stock is delivered into the tank it will be deflected forwardly toward the pipe 2 as indicated by arrows in Figure 1.

An inlet opening 9 is formed transversely in the top of the vat or tank and a suitable dump valve 10 is arranged under the front end portion of the tank or vat where- 'by the contents of said tank or vat can be removed as desired.

The structure hereinbefore described constitutes one unit of the system and it is to be understood that any desired number of these units can be used. The units are to be so positioned that stock flowing up-.

wardly into the openings 9 will be free to flow into troughs 11 connecting the units. These troughs are located at the ends of the openings and are of such depth that the bottoms thereof are some distances below the tops of the vats or tanks as will be seen in Figure 2. A shaft 12 is extended longitudinally within the troughs and secured to this shaft for rotation within each trough are worm conveyors 13 all adapted to propel material in the same direction when the shaft is rotated.

In operation the bleach propellers belonging to the units are set in motion and the shaft 12 is also operated. The paper ulp to be bleached is then supplied to the first tank of the series, this pulp being thoroughly mixed with the chloride of lime liquor or other suitable bleaching a ent. The material thus applied to the tank ows through the pipe 2 into the casing 3 of the bleach propeller and is then forced into the pipes 4 and thence into the vat portion of the tank or vat 1. The jets of fluid discharged into the casings 5 from the pipes 6 tend to accelerate the movement of the material within the pipe and likewise to mix and aerate the material. A continuous circulation of this material is thus effected as indicated by the arrows in Figure 1 and as the levelof the pulp rises in the vat it flows into the adjacent trough 11 and is then propelled by the revolving worm 13 to the opening 9 in the next vat or tank 1 of the series. Here the operation heretofore described is repeated and the material subsequently delivered to the third vat or tank. It will be found that the pulp, after reaching the last vat of the series will be properly bleached and can be removed therefrom. The operation is continuous, the density of of the pulp'acted on is greater than that usually treated, and the bleaching operation can be carried on much more economically and expeditiously than has been found possible with other apparatus provided for similar purposes.

It is to be understood that the tanks or vats can be of any sizes and proportions desired and can also be-made of any suitable material other than that mentioned.

What is claimed is A bleaching apparatus including a plurality of tanks, a propeller communicating with one end of each tank, means for directing fluid from each propeller to the other end of its tank, thereby to set up a circulation of fluid in each tank independently of the circulation of fluid in another tank, means for directing fluid under. pressure into the line of flow of the fluid in each tank, and means for conducting overflow from the circulating fluid in one tank to the circulating fluid in an adjoining tank.

In testimony that I claim the foregoing as my own, I have hereto aflixed my signature.

ALBERT D. MERRILL. 

